src/selectiontoggle.cpp

   1 /***************************************************************************
   2  *   Copyright (C) 2008 by Peter Penz <peter.penz@gmx.at>                  *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA            *
  18  ***************************************************************************/
  19
  20 #include "selectiontoggle.h"
  21
  22 #include <kicon.h>
  23 #include <kiconloader.h>
  24 #include <kiconeffect.h>
  25
  26 #include <QPainter>
  27 #include <QPaintEvent>
  28 #include <QRect>
  29 #include <QTimer>
  30 #include <QTimeLine>
  31
  32 SelectionToggle::SelectionToggle(QWidget* parent) :
  33     QAbstractButton(parent),
  34     m_isHovered(false),
  35     m_fadingValue(0),
  36     m_icon(),
  37     m_fadingTimeLine(0)
  38 {
  39     parent->installEventFilter(this);
  40     resize(sizeHint());
  41     m_icon = KIconLoader::global()->loadIcon("dialog-ok",
  42                                              KIconLoader::NoGroup,
  43                                              KIconLoader::SizeSmall);
  44 }
  45
  46 SelectionToggle::~SelectionToggle()
  47 {
  48 }
  49
  50 QSize SelectionToggle::sizeHint() const
  51 {
  52     return QSize(16, 16);
  53 }
  54
  55 void SelectionToggle::reset()
  56 {
  57     m_item = KFileItem();
  58     hide();
  59 }
  60
  61 void SelectionToggle::setFileItem(const KFileItem& item)
  62 {
  63     m_item = item;
  64     if (!item.isNull()) {
  65         startFading();
  66     }
  67 }
  68
  69 KFileItem SelectionToggle::fileItem() const
  70 {
  71     return m_item;
  72 }
  73
  74 void SelectionToggle::setVisible(bool visible)
  75 {
  76     QAbstractButton::setVisible(visible);
  77
  78     stopFading();
  79     if (visible) {
  80         startFading();
  81     }
  82
  83 }
  84
  85 bool SelectionToggle::eventFilter(QObject* obj, QEvent* event)
  86 {
  87     if ((obj == parent()) && (event->type() == QEvent::Leave)) {
  88         hide();
  89     }
  90     return QAbstractButton::eventFilter(obj, event);
  91 }
  92
  93 void SelectionToggle::enterEvent(QEvent* event)
  94 {
  95     QAbstractButton::enterEvent(event);
  96
  97     // if the mouse cursor is above the selection toggle, display
  98     // it immediately without fading timer
  99     m_isHovered = true;
 100     if (m_fadingTimeLine != 0) {
 101         m_fadingTimeLine->stop();
 102     }
 103     m_fadingValue = 255;
 104     update();
 105 }
 106
 107 void SelectionToggle::leaveEvent(QEvent* event)
 108 {
 109     QAbstractButton::leaveEvent(event);
 110     m_isHovered = false;
 111     update();
 112 }
 113
 114 void SelectionToggle::paintEvent(QPaintEvent* event)
 115 {
 116     QPainter painter(this);
 117     painter.setClipRect(event->rect());
 118
 119     if (m_isHovered) {
 120         KIconEffect iconEffect;
 121         QPixmap activeIcon = iconEffect.apply(m_icon, KIconLoader::Desktop, KIconLoader::ActiveState);
 122         painter.drawPixmap(0, 0, activeIcon);
 123     } else {
 124         if (m_fadingValue < 255) {
 125             // apply an alpha mask respecting the fading value to the icon
 126             QPixmap icon = m_icon;
 127             QPixmap alphaMask(icon.width(), icon.height());
 128             const QColor color(m_fadingValue, m_fadingValue, m_fadingValue);
 129             alphaMask.fill(color);
 130             icon.setAlphaChannel(alphaMask);
 131             painter.drawPixmap(0, 0, icon);
 132         } else {
 133             // no fading is required
 134             painter.drawPixmap(0, 0, m_icon);
 135         }
 136     }
 137 }
 138
 139 void SelectionToggle::setFadingValue(int value)
 140 {
 141     m_fadingValue = value;
 142     if (m_fadingValue >= 255) {
 143         Q_ASSERT(m_fadingTimeLine != 0);
 144         m_fadingTimeLine->stop();
 145     }
 146     update();
 147 }
 148
 149 void SelectionToggle::startFading()
 150 {
 151     Q_ASSERT(m_fadingTimeLine == 0);
 152
 153     m_fadingTimeLine = new QTimeLine(2000, this);
 154     connect(m_fadingTimeLine, SIGNAL(frameChanged(int)),
 155             this, SLOT(setFadingValue(int)));
 156     m_fadingTimeLine->setFrameRange(0, 255);
 157     m_fadingTimeLine->start();
 158     m_fadingValue = 0;
 159 }
 160
 161 void SelectionToggle::stopFading()
 162 {
 163     if (m_fadingTimeLine != 0) {
 164         m_fadingTimeLine->stop();
 165         delete m_fadingTimeLine;
 166         m_fadingTimeLine = 0;
 167     }
 168     m_fadingValue = 0;
 169 }
 170
 171 #include "selectiontoggle.moc"